Newbie Question: Best RPM for fuel efficiency - 300XS

[H2OSOFAST]

Hello, I am new to the forum and Go Fast Boats. I recently purchased a 21 Liberator with a 300XS. We have really enjoyed the boat now that we have taken it out a couple of times. I am having difficulty finding out what the best RPM is for fuel efficiency on this set up. It currently has 31 Drag Four prop.

We are heading out in the morning to the St Johns river to explore some parts of the river I have not been on yet (North of Dunns Creek) and would like to get the longest range possible.

I appreciate any RPM recommendations anyone can offer.

[engineermike]

The vast majority of boats get best fuel economy at the lowest planing speed possible. Sometimes, air entrapment hulls do a little better once you get some air under it, which is a little faster. I had a test a while back, where a 30' Skater got the same fuel economy at 60 mph as it did at 30, whereas it was worse at speeds in between.

[rock]

Most everything I have seen tested peaks out mileage wise at 3000 to 3500 rpms.

Rock

[jag3639]

I have always run 92 grade. I have tested with lower grade fuels. Dont see a difference in mileage but if I dump more oil as needed it helps the carbs from running rich. Of course over a few months of boating. Just burns cleaner and faster.

[Euroski]

On my 22 Cougar MTR w/300xs and Bravo 1 28p, smartcraft shows about 6.5 gal/hr at about 3500rpm.

[H2OSOFAST]

Great feedback. Thank you for the advice!